According to the related art, in order to form a microlens in the process of manufacturing an image sensor, a micro-photo process is typically performed by using a photoresist for the microlens and then performing a reflowing process.
However, a large amount of photoresist is lost during the reflowing process, thereby forming a gap between adjacent microlenses. As a result, the amount of light introduced into a photodiode is reduced, leading to an image defect for the image sensor.
In addition, according to the related art, in the case of a microlens formed using organic material, particles generated when a wafer sawing process is performed (e.g., a package process or a bump process in a semiconductor chip mounting process) may cause damage to the microlens. In addition, image defects may be caused if the particles adhere to the microlens.
Moreover, according to the related art, when the microlens is manufactured, a difference in focal length often occurs between a cross axis and a diagonal axis, leading to crosstalk in adjacent pixels.
Accordingly, there exists a need in the art for an improved method for manufacturing an image sensor.